Soil conservation is a matter of concern worldwide, and especially in the United States. It has been estimated that at one time there was an average of 18 inches of top soil in the United States and that has now been reduced to a mere 8 inches. This loss of topsoil may have profound negative implications for world food supplies if it is allowed to continue.
Most topsoil loss is caused by water erosion; that is, the topsoil is carried off with rainwater and melting snows and eventually reaches rivers. This brings about the additional problems of the silting and polluting of rivers and clogging of otherwise navigable waterways.
Numerous attempts have been made to inhibit erosion, with varying degrees of success.
However, applicant is not aware of any proposals which provide the effective protection of hillsides against erosion with as little cost and labor required as in applicant's invention, as described hereinafter.
Erosion generally occurs when water in excess of the amounts capable of being absorbed falls on land in the form of rain. Additional water may be supplied by melting snow and ice. Under the influence of gravity the water flows toward the lowest point, where it joins with similar flows, eventually building into a rivulet of increasing volume. The moving water in the rivulet entrains soil particles and carries them downstream. The greater the rate of flow, the greater the tendency to entrain and carry soil particles downstream. Accordingly, to the extent that the flow rate can be minimized or, where high flow rates exist, isolated from the soil, the less the soil will be eroded.
In addition, it is often desirable to retain water in the soil, rather than allowing it to flow downstream during a brief, heavy rain, such as a thunderstorm. In a thunderstorm the rate of precipitation may be so great that the water has very little time to penetrate the soil where it can be stored for later use by plants, and instead merely runs along the surface, eroding the surface and passing downstream to rivers, lakes and the sea.
Accordingly, there is a need in the art not only for a method and apparatus for inhibiting erosion, but also for returning fast moving water to the subsoil where it can be absorbed and used as needed by growing plants, or tapped by men and women.